James O'Keefe, the young conservative filmmaker who was behind the undercover operations that led to the ACORN scandal last year, was arrested with three others for allegedly trying to tamper with the phones at the New Orleans office of Sen. Mary Landrieu (D-LA) yesterday.

The FBI announced today the foursome have been charged with entering federal property under false pretenses for the purpose of committing a felony.

The affidavit alleges that the botched phone tampering began with two of the four men -- Joseph Basel and Robert Flanagan, both 24 -- entering Landrieu's office in downtown New Orleans in Village People-style construction worker garb, claiming they were telephone repairmen.

Each man was wearing blue denim pants, a blue work, shirt, a light fluorescent green vest, a tool belt, and carrying white, construction-style hard hat, when they allegedly asked a staffer to show them to the telephone closet.

O'Keefe, meanwhile, was already in the office, and he allegedly told the Landrieu staffer he was "waiting for someone to arrive." The affidavit alleges O'Keefe held up his cell phone to record Basel and Flanagan.

Also arrested was Stan Dai, accused of aiding Basel and Flanagan. The news of the arrests was first reported by the Times-Picayune.

O'Keefe was apparently in town as early as last Thursday to give a speech at the Pelican Institute, a libertarian think tank in New Orleans.

The AP is reporting that Flanagan is the son of acting U.S. Attorney Bill Flanagan in Shreveport. Reached by TPM today, Flanagan's office said he is not talking to the press.

The ACORN stings that made O'Keefe's name were posted on Andrew Breitbart's Big Government Web site. Reached by TPM this afternoon, Breitbart said: "I need to find information on this. I'm out of the loop on this. I will make my determination then on when to comment."

Breitbart later toldPolitico: "We have no knowledge about or connection to any alleged acts and events involving James O'Keefe at Senator Mary Landrieu's office. We only just learned about the alleged incident this afternoon."

Said Landrieu spokesman Aaron Saunders: "Because the details of yesterday's incident are part of an ongoing investigation by federal authorities, our office cannot comment at this time."

On or about Januart 25, 2010, at approximately 11:00 a.m., Flanagan and Basel entered the Hale Boggs Federal Building, each dressed in blue denim pants, a blue work, shirt, a light fluorescent green vest, a tool belt, and carrying white, construction-style hard hat. Basel and Flanagan went to the tenth floor of the building and entered the office of United States Senator Mary Landrieu. According to Witness 1, a member of Senator Landrieu's staff who was working in her New Orleans office at the time of the incident, James O'Keefe was already present in the office. O'Keefe informed Witness 1 that he was waiting for someone to arrive. ...

Witness 1 further state that when Flanagan and Basel entered the office, O'Keefe positioned his cellular phone in his hand so as to record Flanagan and Basel.

...

Thereafter, Flanagan and Basel told Witness 1 that they needed to perform repair work on the main telephone system and asked for the location of the telephone closet. Witness 1 directed Flanagan and Basel to the main [General Services Administration] office, located on the tenth floor of the Hale Boggs Federal Building. Both men went to the GSA office.

Flanagan and Basel spoke with Witness 2, a GSA employee working the GSA office, and represented that they were employees of the telephone company and needed access to the telephone closet to perform repair work. Witness 2 asked the men for credentials, and Flanagan and Basel state that they had left their credentials in their vehicle.

Further investigation has determined that neither Flanagan nor Basel are employed by any telephone company, and that neither individual is a telephone repairman.

The affidavit goes on to allege that Flanagan and Basel admitted to federal agents that they entered Landrieu's office under false pretenses. It also alleges that O'Keefe and Dai admitted they helped plan and execute the operate, and that O'Keefe admitted he recorded his companions in Landriee's office.

It's unclear why O'Keefe and his companions decided to target Landrieu. She was most recently the target of GOP ire for the so-called "new Louisiana Purchase" -- a reference to $100 million in extra Medicare subsidies she won for her state in the Senate health bill.